Earth boring apparatus



Feb. 22, DORKINS T L EARTH BORING APPARATUS Filed Feb. 6, 1963 5 Sheets-Sheet 2 INVENTORS 6 EVAN E. DORKINS BY DANIEL H. ZWIGHT gg zguvm ATTORNEYS 1956 E. E. DORKINS ETAL 3,235,315

EARTH BORING APPARATUS Filed Feb. 6, 1965 5 Sheets-Sheet 3 INVENTORS EVAN E. DORKINS BY DANIEL H. ZWIGHT fiawm y m ATTORNEYS Feb. 22, 1966 E. E. DORKKNS ETAL 3,236,316

EARTH BORING APPARATUS Filed Feb. 6, 1963 5 Sheets-Sheet 4.

IN VEN TORS EVAN E. DORKINS y DANIEL H. ZWIGHT ATTORNEYS 1966 E. E. DORKINS ETAL 3,236,316

EARTH BORING APPARATUS Filed Feb. 6, 1965 5 ShQBtS-Sht 5 T n W INVENTORS EVAN E. DORKINS 4 BY DANIEL H. ZWIGHT 9 9 fiwfmym ATTORNEYS United States Patent 3,236,316 EARTH BORING APPARATUS Evan E. Dorkins, Bay Village, Ohio, and Daniel H. Zwight, Griffin, Ga., assignors, by mesne assignments, to The Ohio Brass Company, Mansfield, Ohio, 21 corporation of New Jersey Filed Feb. 6, 1963, Ser. No. 256,623 13 Claims. (Cl. 173-16tl) This invention relates in general to earth boring apparatus of the type supported on or suspended from a derrick or crane, for digging operations, and more particularly to such type of apparatus wherein the earth boring apparatus is adapted to be swung upwardly to a generally laterally disposed storage position with respect to the boom when not in use.

Such type of apparatus is conventionally found in conjunction with a utility type of vehicle and is adapted for handling and erecting various objects, such as telephone or telegraph poles, and may be effectively utilized in performing all of the necessary work operations associated with setting a utility line pole in proper place along a thoroughfare or the like.

In the United States Patent No. 3,073,455 of George H. Eckels et -al., issued January 15, 1963, there is disclosed a portable type derrick mounted on a utility type vehicle of the above discussed type. The derrick disclosed in such application comprises a sectional, extensible boom and includes means on the boom for attaching an associated work mechanism, such as an earth boring tool, to the boom, and with such means comprising a support or collar member mounted on the extendible section of the boom and projecting laterally therefrom, with the earth boring tool being suspended from such laterally projecting portion of the collar. The collar member is adapted for lengthwise movement with respect to the boom, for adjusting the position of the earth boring auger lengthwise along the boom.

The present invention provides a novel arrangement of earth boring derrick wherein the earth boring auger supporting member is rotatable with respect to the section of the boom on which it is supported, and which may be moved or rotated in a direction generally transverse of such boom section, so that the earth boring auger may be disposed generally beneath the boom, rather than laterally to one side thereof, during earth boring operations, and wherein the supporting member and associated auger may be moved or rotated to a generally laterally disposed position with respect to the boom, when it is desired to place the earth boring auger in storage position.

Accordingly, an object of the invention is to provide a novel arrangement of earth boring derrick.

Another object of the invention is to provide a novel arrangement of derrick with a vertically swingable boom having a member thereon for supporting an associated work mechanism, such as for instance an earth boring tool, and which member is movable or rotatable with respect to the derrick boom, so that the work mechanism can be positioned generally in alignment with the derrick boom for work operations and can be positioned generally laterally of the derrick boom for storage.

A more specific object of the invention is to provide a portable type derrick including a vertically swingable, sectional, extensible boom, providing for telescopically varying the eflective length of the boom, and wherein there is provided a support member on the extensible section of the boom, which support member mounts a work mechanism, such as an earth boring auger thereon,

and which support member is rotatable with respect to the boom, so that the auger may be moved downwardly to be disposed beneath the boom during work or drilling "ice operations, and which support member may be rotated so as to position the earth boring mechanism generally laterally of the boom, for convenient storage of the work mechanism with respect to the boom, and wherein there is provided novel means for selectively securing the work mechanism support member to either the extensible boom section, or to the relatively stationary section of the boom, thereby providing for adjusting the position of the work mechanism lengthwise along the boom.

Other objects and advantages of the invention will be apparent from the following description taken in conjunction with the accompanying drawings wherein:

FIG. 1 is a fragmentary, side elevational view of the derrick of the invention as mounted on a utility type of vehicle, and illustrating an earth boring auger suspended from adjacent the outer end of an extensible derrick boom by a work mechanism supporting member with the auger being urged into the ground by the derrick;

FIG. 2 is a top plan, generally diagrammatic view of the derrick and associated earth boring tool of FIG. 1, as mounted in storage position on the vehicle, with the earth boring tool having been swung upwardly into generally laterally disposed orientation with respect to the derrick boom;

FIG. 3 is an enlarged, fragmentary, side elevational view of the outer end of the inner section of the extensible derrick boom, and particularly illustrating bracket means thereon for securing the work mechanism supporting member to such boom inner section, for permitting extension of the outer section of the boom with respect to the inner boom section and attached Work mechanism, and yet also providing for rotational movement of the work mechanism supporting member in a direction generally transverse of the boom and with respect to such bracket means;

FIG. 4 is a top plan view of the FIG. 3 illustration;

FIG. 5 is a front elevational view of the bracket means shown in FIGS. 3 and 4;

FIG. 6 is a top plan view of a bracket means adapted for attachment to the outer boom section, for securing the work mechanism supporting member to such outer boom section, for movement of the work mechanism with the outer boom section, and yet providing for rotational movement of the work mechanism supporting member with respect to said bracket means;

FIG. 7 is an elevational view of the FIG. 6 bracket; in section is shown the boom mounting such bracket;

FIG. 8 is a side elevational view of the FIG. 6 bracket taken from the right hand side thereof;

FIG. 9 is an elevational view of the work mechanism supporting member, which supporting member is adapted for rotational movement with respect to the supporting section of the boom and with respect to the above dis cussed bracket means of FIGS. 3 to 5 and FIGS. 6 to 8;

FIG. 10 is a front elevational view of the supporting member illustrated in FIG. 9, taken generally from the right hand side thereof;

FIG. 11 is a front elevational view of a carriage member adapted for attachment to the work mechanism supporting member of FIGS. 9 and 10 and which is adapted for suporting extensible, telescoping fluid transmission lines, for furnishing pressurized fluid to the fluid motor of the work mechanism or earth boring auger;

FIG. 12 is an elevational view of the FIG. 11 carriage; in FIGS. 7 and 8 there is shown this carriage in position with respect to the bracket means which is adapted to secure the work mechanism supporting member to the outer boom section.

Referring now again to the drawings, there is shown a wheeled utility vehicle 10 having a truck body which carries a movable derrick 12 thereon. The derrick boom may be mounted on a pedestal 14 adapted for rotational movement about a generally vertical axis, for swinging of the boom in a generally horizontal plane. Conventional power means, including control means, may be provided for so selectively swinging the boom through any desired range.

The boom may be pivoted adjacent the lower end thereof, as at 16, for swinging movement in a generally vertical plane with respect to the vehicle. This swinging movement of the boom in a generally vertical plane may be from a position below a horizontal plane passing through axis 16, to a position well above such horizontal plane and vice versa. Fluid powered reciprocal motor means 18 mounted on the pedestal frame 19 and operatively coupled to the derrick boom may be provided for so swinging the boom in a generally vertical plane.

The derrick boom illustrated embodies an inner or lower, generally hollow boom section 22, pivoted as aforementioned as at 16, to the pedestal frame, and an outer generally hollow extendible section 26, which may be received in telescoping relation in the lower or inner section 22 of the boom. The boom sections are preferably of rectilinear configuration in vertical cross section. A reciprocal, fluid powered motor unit may be disposed interiorly of the boom sections for extension and retraction of the extendible section in a manner known in the art. The outer end of the boom may be provided with a conventional head sheave assembly 28 adapted for coacting with a flexible lift cable 28a, for handling objects in the conventional manner. Reference may be had to the aforementioned United States Patent 3,073,455 for a more detailed description of derrick construction suitable for the instant arrangement.

The earth boring mechanism 35, in the embodiment illustrated, is selectively coupleable to either the extendible section 26 of the boom, or to the relatively stationary section 22 of the boom. The arrangement for so accomplishing the latter may comprise a tool supporting member 36 mounted on the extendible section 26 of the boom and which may comprise a collar-like portion 38 (FIGS. 9 and 10), and an arm portion 38a projecting generally radially outwardly from the collar portion 38. Arm 38a may include a bifurcated portion 38b adjacent its outer end, which is apertured, as at 380, for receiving therebetween in pivotal relation, as at 39, the conventional supporting handle or structure 40 (FIGS. 1 and 2) of the transmission housing 42 of the earth boring tool.

As can be best seen in FIGS. 9 and 10, the collar portion 38 of member 36 is preferably provided with a circumferential, interior groove 43, for a purpoe to be hereinafter described, and is also provided with axially spaced,

exterior lugs or shoulders 44, 46 disposed on opposite circumferential surfaces of the collar. Lugs 44 are of much lesser circumferential length as compared to lugs 46, and with lugs 44 being disposed adjacent the rear surface 50 of collar portion 38 while lugs 46 are disposed adjacent the front surface 52 of collar portion 38. In the embodiment illustrated, each of lugs 46 extends circumferentially for about 110 of the 180 respective half of the collar portion, while each of lugs 44 extends circumferentially for approximately 30 of the 180 respective half of the collar portion.

Secured to the outer end of the inner section 22 of the derrick boom is a bracket member 55 (FIGS. 3, 4 and which includes locking lugs 55a, 55b on the upper and lower edges thereof, which lugs project toward the free end of the boom. Such bracket 55 also includes a segmental, circumferentially extending bearing portion 56 which is adapted to rotatably mount the aforementioned tool supporting member 36 thereon. In other words, the interior diameter of the opening 57 in the tool supporting member is just slightly greater than the exterior diameter of the segmental bearing portion 56. Bracket member 55 has a generally rectilinear shaped opening 60 extending therethrough which open g is a apted to receive there- .motor 88 (FIG. 1) of the earth borer.

through the outer section 26 of the boom, so that the boom is slidable or movable lengthwise with respect to bracket member 55, and with the boom section 26 being facilitated in its lengthwise movement by the rollers 62 pivotally mounted as for instance at 64 on the inner boom section 22 and adapted to extend into rolling engagement with the outer boom section 26.

From FIGS. 2 and 9 it will be apparent that when the tool supporting member 36 is rotated approximately 90 about the axis of the outer boom section, or until the rearwardly disposed lugs 44 engage or coact in overlapped, interlocking relation with the lugs 55a, 55b on the bracket member 55, the tool supporting member 36 and accordingly the work mechanism or earth boring tool 35 will be locked to or held secured with the inner section 22 of the boom. In such a position, the arm 38a of the tool supporting member will extend generally laterally of the boom (FIG. 2) and the auger may be readily swung toward the boom and about pivot 39, and be gripped or detachably interlocked by conventional bracket 66 extending generally laterally from the boom. Thus the tool can be disposed generally laterally of the boom and secured in inactive or stored position, and may be carried in such position substantially completely within vertical planes defining the confines or exterior configuration of the vehicle (FIG. 2) so that no material part of the earth boring tool or boom projects outwardly of the vehicle. It will be seen, therefore, that the bracket member 55 can selectively interlock the tool supporting collar 36 to the inner boom section 22, and when in such interlocked condition, the outer section 26 of the boom can be moved lengthwise with respect to the inner boom section and coupled tool supporting member 36 interlocked with the bracket 55.

Attached adjacent the outer end of the outer section 26 of the boom, and preferably to the head sheave assembly 28 on such boom outer end, there is provided another bracket means 68 (FIGS. 6, 7 and 8) which other bracket 68 likewise has a generally rectilinear opening 70 therethrough, receiving the outer section 26 of the boom, and which also has a circumferential bearing portion 72 for rotatably mounting the tool supporting member 36. Bracket 68 also has locking lugs 74 disposed on opposite lateral extremities thereof, which locking lugs 74 are adapted for interlocking coaction with the aforementioned flanges or shoulders 46 on the tool supporting collar 36 when the tool supporting collar has been rotated to bring lugs 46 into overlapping, interlocked coaction with lugs 74 on the bracket 68. The bearing portion 72 of the bracket 68 has an exterior diameter of just slightly less than the interior diameter of the opening 57 in collar portion 38 of the tool supporting member 36, and preferably has an axial dimension at least as great as the axial dimension of collar portion 38. The bracket also preferably has a slot 76 completely therethrough and which is adapted to receive therein a carriage 78 (FIGS. 11 and 12) which includes wheels or rollers 78a rollingly engaging the top surface of the outer section 26 of the boom. This carriage may include a pin 80 projecting upwardly from its top surface 82 and receivable in the aforementioned interior slot 43' in the tool supporting collar member 36, for maintaining the carriage 78 and collar member 36 in assembled relation, while permitting rotation of the collar member with respect to the carriage. As may be best seen from FIG. 8, top surface 82 of the carriage forms a generally continuation of the exterior bearing surface of bearing portion 72 of bracket 68. The forward end of the carriage includes a support 84 having openings 84a therethrough which receive and support telescopically extensible fluid transmission lines 86 (FIG. 1) on the boom, for the supplying of pressurized actuating fluid to the Motor 88 may be mo nted in the conventional manner on transmission housing 42 and may be connected to a source of pressurized fluid by flexible hose 88a in a known manner.

Since the carriage 78 moves with the tool supporting collar member 36, and since the collar member supports the earth borer, it will be seen that the extensible fluid lines 86 always move, or extend and retract, with movement of the collar member 36 and associated earth boring mechanism. Reference may be had to US. Patent No, 3,073,396 issued January 15, 1963 to George H. Eckels, for a detailed disclosure of suitable extensible fluid transmission line means which may be used with the instant arrangement.

When the collar member 36 is attached by means of its lugs 46 to the bracket means 68 on the outer boom section 26, the collar member 36 rides or is carried by bearing portion 72 of bracket 68, and the carriage 78 is disposed Within the slot 76 in the bracket member 68, and therefore there is no interference between the carriage and the bracket member during extension and retraction of the fluid transmission line means 86 upon outward and inward movement of the outerboom section with respect to the inner boom section, to move the earth boring tool with the outer boom section.

When the collar 36 has been so rotated that the lugs 44 on the collar are coacting with the lugs 55a, 55b on the bracket 55 secured to the inner boom section, the collar 36 and associated carriage 78 are retained with the inner boom section 22, and the outer boom section 26 may be moved lengthwise with respect to the inner boom section and coupled work mechanism 35. When the earth borer is released from its interlocked coaction with bracket 66 on the inner boom section, thus permitting the collar member 36 to rotate about the axis of the boom, the earth boring auger and associated arm 38a of the collar member 36 are disposed generally directly beneath the center line of the boom, and thus the effective drilling pressure occasioned by the downward pivotal movement of the boom about axis 16 (FIG. 1) is greatly increased over that which could be provided by a laterally disposed earth boring mechanism. After finishing of the boring operation, the outer boom section 26 and coupled earth boring tool can be retracted into the inner boom section 22, and then the collar member 36 can be rotated as for instance manually, so that lugs 44 on the collar are interlocked with the lugs a, 5512 on the bracket 55 on the inner boom section, and the earth boring auger can be swung into generally parallel orientation with respect to the boom and locked by bracket 66 in storage position thereon.

The terms and expressions which have been used are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of any of the features shown or described, or portions thereof, and it is recognized that various modifications are possible within the scope of the invention claimed.

We claim:

1. In a derrick comprising a boom, said boom comprising an inner section and an outer section disposed in telescopic relation with respect to the inner section, means for telescopically moving said outer boom section with respect to said inner boom section, means pivotally mounting said inner boom section on a support for swinging movement of the boom in a generally vertical plane, a work mechanism supporting member mounted on said boom and adapted to support a work mechanism such as an earth boring auger thereon, said boom being adapted to apply a downward force to said supporting member and associated work mechanism during work operations, said supporting member including a collar-like portion adapted for rotational movement with respect to the inner boom section about the lengthwise axis of the boom and in a direction generally transversely of the boom, and an arm portion extending generally radially outwardly from said collar-like portion, said arm portion being substantially centrally aligned with said collar-like portion in directions lengthwise and crosswise of said boom, said arm portion having means thereon substantially aligned with said arm portion for pivotally supporting the work mechanism, and means on said outer boom section adapted for coupling relation with means on said collar-like portion to cause movement of said supporting member and attached work mechanism with said outer boom section and with respect to said inner boom section, said arm portion and associated work mechanism being disposable substantially directly beneath the boom for digging operations upon predetermined rotation of said supporting member for causing substantially the full force of said boom to be applied to said supporting member and associated work mechanism for urging the work mechanism into the ground, said supporting member being disposable generally laterally of the boom for storage of the work mechanism upon reverse rotation of said supporting member.

2. A derrick in accordance with claim 1 including means on said inner boom section adapted for releasable coupling with means on said collar-like portion for detachably locking said suporting member and associated work mechanism to said inner boom section upon predetermined rotation of said rotation of said collar-like portion toward storage position.

3. A derrick in accordance with claim 2 wherein said coupling means on each of said outer and inner boom sections includes a cylindrical-like bearing portion disposed in generally encompassing and aligned relation with the axis of said boom for rotatably mounting said collarlike portion thereon.

4. A derrick in accordance with claim 2 wherein said means on said collar-like portion comprises axially-spaced circumferentially extending exterior flanges thereon, said coupling means on said outer and inner boom sections each comprises exterior, diametrically opposed lugs adapted for overlapping interlocking coaction with respective of said flanges upon predetermined rotation of said supporting member.

5. A derrick in accordance with claim 1 including anti-friction carriage means supported on said outer boom section, extensible fluid transmission line means supported on the boom by the carriage means, said line means being adapted for furnishing pressurized fluid to said work mechanism, and means coupling said supporting member to said carriage means for lengthwise movement of said carriage means and coupled supporting member during lengthwise movement of said outer boom section when the latter is coupled to said supporting member, and means providing for rotation of said supporting member with respect to said carriage means.

6. A derrick in accordance with claim 1 wherein said boom is mounted on a pedestal which is rotatable about a generally vertical axis.

7. In a derrick comprising a vertically pivotal boom, said boom being of the selectively extensible type including an outer section movable lengthwise with respect to the remainder of the boom, means on said boom for attaching an associated work mechanism thereto, said means comprising a work mechanism supporting member, said supporting member comprising a collar-like portion generally encompassing said boom, means on said supporting member and on said outer boom section for coupling said supporting member to said outer boom section for lengthwise movement of said supporting member with said outer boom section, said collar-like portion being rotatable with respect to said boom and about the lengthwise axis of said boom in a direction generally transverse of the boom, whereby the work mechanism may be disposed substantially directly beneath the boom for work operations or laterally to a side thereof for storage, said boom being adapted to apply a downward force to said supporting member and associated work mechanism to urge the latter into the ground during work operations, and means projecting outwardly from said collar-like portion for attaching the work mechanism thereto, the last mentioned means being disposed substantially in centralized alignment with said collar-like portion in directions lengthwise and crosswise of the boom whereby the work mech anism will be substantially aligned with said collar-like portion and said last mentioned means for causing the full force of the boom to be applied to the work mechanism during work operations.

8. A derrick in accordance with claim 7 including extensible, fluid transmission line means mounted on said boom for transmitting pressurized actuating fluid to and from the work mechanism, and carriage means supporting said line means in secured relation to said carriage means on said outer boom section, said carriage means and said supporting member including means coupling said carriage means and said supporting member together, for causing lengthwise movement of said line means with movement of said supporting member lengthwise of the boom, while providing for said rotary movement of said supporting member generally transversely of said boom.

9. A work mechanism support for a vertically pivotal derrick comprising, collar-like means for mounting the support on the derrick boom in generally encompassing relation thereto, means extending generally radially outwardly from the collar-like means for suspending the work mechanism such as an earth boring auger from the support, said radial means being substantially aligned with said collar-like means in directions lengthwise and crosswise of the collar-like means, said support being adapted to apply the downward force of the boom to the work mechanism for digging operations, said collar-like means including exterior, axially spaced pairs of flanges extending generally circumferentially of said collar-like means, the flanges of each of said pairs being disposed in diametrically opposed relation, with the flanges of one of said pairs extending a greater circumferential amount than the flanges of the other of said pairs, said flanges being adapted to detachably couple said work mechanism support to the derrick boom in predetermined positions of said work mechanism support, and means providing for rotary movement of the work mechanism support with respect to and transversely of the derrick boom and about the lengthwise axis of the boom.

10. A support in accordance with claim 9 wherein said radial means comprises a linear arm extending laterally outwardly from the collar-like portion, and means on said arm and aligned therewith for pivotally suspending the work mechanism therefrom.

11. A derrick comprising a boom, said boom comprising an inner section and an outer section disposed for relative lengthwise movement with respect to the inner section, means for moving said outer boom section lengthwise with respect to said inner boom section, means for pivotally mounting said inner boom section on a support for swinging movement of the boom in a generally vertical plane, a work mechanism supporting member mounted on said boom and supporting a fluid powered earth boring auger thereon, said boom being adapted to apply a downward force to said supporting member and thus to the auger for forcing the auger into the ground during digging operations, said supporting member comprising a generally cylindrical-like collar portion adapted for rotational movement with respect to the boom about the lengthwise axis of the boom in a direction generally transversely of the boom and an arm portion extending generally radially outwardly from said collar portion, said arm portion being substantially aligned with said collar portion in directions lengthwise and crosswise of said boom, said arm portion having pivot means thereon for pivotally supporting the earth boring auger, said pivot means being substantially aligned in directions lengthwise and crosswise of the boom with said arm portion, and a cylindrical-like bearing means on said outer boom section adapted to receive said collar portion thereon in generally encompassing relation, exteriorly disposed axially spaced flange means on said collar portion extending generally circumferentially in diametrically opposed relation, said bearing means having diametrically opposed flange means thereon adapted for coupling relation with certain of the flange means on said collar portion, to cause lengthwise movement of said supporting member and auger and with respect to said inner boom section upon lengthwise movement of said outer boom section with respect to said inner boom section, said arm portion and associated auger being disposable directly beneath the boom for digging operations upon predetermined downward rotation of said supporting member with respect to said boom, said supporting member being rotatable so as to dispose said arm portions laterally of said boom for storage of the auger upon reverse rotation of said supporting member, and bearing means including diametrically opposed flange means on said inner boom section adapted for coupling with other of said flange means on said collar portion upon rotation of said collar portion to dispose said arm portion laterally of said boom, whereby said outer boom section may move lengthwise with respect to said inner boom section and coupled supporting member.

12. A derrick in accordance with claim 11 including telescopic fluid transmission line means mounted on said boom for transmitting pressurized actuating fluid to and from said auger, a wheeled carriage mounted on said outer boom section, means on said carriage for supporting said line means thereon, said collar portion encompassing said carriage, and means on said carriage coacting with means on said collar portion for coupling the carriage to said collar portion for lengthwise movement of the carriage with lengthwise movement of the collar portion, said carriage coupling means comprising a pin projecting upwardly from said carriage and interior circumferential slot means in said collar portion coacting with said pin to couple the carriage to said collar portion while permitting rotary movement of said collar portion with respect to said carriage.

13. A derrick in accordance with claim 12 wherein said bearing means on said outer boom section includes a passageway therein into which is adapted to move said carriage upon movement of said bearing means on said outer boom section into said supporting member.

References Cited by the Examiner UNITED STATES PATENTS 2,317,729 4/1943 Bruno 285-377 2,732,751 1/1956 Heidecke et al. 2854()1 3,073,396 1/1963 Eckels 17338 3,073,455 l/l963 Eckels et al l7328 3,116,840 1/1964 Carbert et a1. 214-3 BROUGHTON G. DURHAM, Primary Examiner. 

9. A WORK MECHANISM SUPPORT FOR A VERTICALLY PIVOTAL DERRICK COMPRISING, COLLAR-LIKE MEANS FOR MOUNTING THE SUPPORT ON THE DERRICK BOOM IN GENERALLY ENCOMPASSING RELATION THERETO, MEANS EXTENDING GENERALLY RADIALLY OUTWARDLY FROM THE COLLAR-LIKE MEANS FOR SUSPENDING THE WORK MECHANISM SUCH AS AN EARTH BORING AUGER FROM THE SUPPORT, SAID RADIAL MEANS BEING SUBSTANTIALLY ALIGNED WITH SAID COLLAR-LIKE MEANS IN DIRECTIONS LENGTHWISE AND CROSSWISE OF THE COLLAR-LIKE MEANS, SAID SUPPORT BEING ADAPTED TO APPLY THE DOWNWARD FORCE OF THE BOOM TO THE WORK MECHANISM FOR DIGGING OPERATIONS, SAID COLLAR-LIKE MEANS INCLUDING EXTERIOR, AXIALLY SPACED PAIRS OF FLANGES EXTENDING GENERALLY CIRCUMFERENTIALLY OF SAID COLLAR-LIKE MEANS, THE FLANGES OF EACH OF SAID PAIRS BEING DISPOSED IN DIAMETRICALLY OPPOSED RELATION, WITH THE FLANGES OF ONE OF SAID PAIRS EXTENDING A GREATER CIRCUMFERENTIAL AMOUNT THAN THE FLANGES OF THE OTHER OF SAID PAIRS, SAID FLANGES BEING ADAPTED TO DETACHABLY COUPLE SAID WORK MECHANISM SUPPORT TO THE DERRICK BOOM IN PREDETERMINED POSITIONS OF SAID WORK MECHANISM SUPPORT, AND MEANS PROVIDING FOR ROTARY MOVEMENT OF THE WORK MECHANISM SUPPORT WITH RESPECT TO AND TRANSVERSELY OF THE DERRICK BOOM AND ABOUT THE LENGTHWISE AXIS OF THE BOOM. 